You’ve now learned that infants acquire the phonemic categories of their native language very young, even before they can reliably produce sounds or words! This is one of the reasons that it can be challenging to learn another language when we’re older, because our mind has already set up phoneme categories for our native language and has learned to efficiently categorize speech sounds into these native categories. Learning a new language can involve dividing up existing categories into new ones, shifting the boundaries of our L1 categories, or creating entirely new categories for our L2.